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5.3.7 Accounting for currents due to reactive power in the system <br />There is always a certain amount of reactive power generated in the system due to the presence of <br />capacitors inside the PV microinverters. Due to the presence of this reactive power in the system, the <br />current from the system can never be completely curtailed down to 0. <br />This does not impact our functionality of limiting export to the grid in any way because reactive <br />power is not accounted for by utilities when measuring the export from DER to the utility grid. Utilities <br />calculate exports based on the active power component. However, this current due to reactive power <br />must be considered when using Enphase Power Control to control the export current from the DER to <br />the main panel to avoid a main panel upgrade. <br />Handling reactive power when the current limit is derived based on the NEC 120% rule <br />If the installer enters a system configuration such that the total current in the system due to reactive <br />power will exceed the limit to which the export current needs to be curtailed based on the NEC 120% <br />rule, the installer will see a pop-up such as the one mentioned in the following figure. <br />The installer will have the option to click CANCEL and re-enter the system configuration if required <br />or click CONTINUE and proceed. If the installer chooses to proceed, then the system limits the export <br />current to the current generated due to the reactive power generated in the system and cannot limit <br />it to any value below that. Therefore, there is a possibility of the system not being compliant with the <br />NEC 120% rule. <br />Handling reactive power when the current limit is directly entered by the installer <br />Enphase Power Control features <br />37 © 2025 Enphase Energy Inc. All rights reserved. August 2025 <br />TEB-00269-2.0-EN <br />We must account for the presence of currents due to reactive power in the system. If the installer <br />enters a value that is lower than the total current generated by reactive power in the system, the <br />pop-up is displayed as shown, asking the installer to re-enter an appropriate value. <br />5.4 Aggregate power export limit <br />The aggregate power export limit feature ensures that the power exported by the <br />Enphase Energy System across all phases, that is, aggregate power, to the grid does not exceed <br />the power export limit set in the Enphase Installer App by the installer. <br />The Enphase Energy System continuously monitors the aggregate exported power at the point of <br />measurement, that is, at the Consumption CTs or IQ Meter Collar, and controls the power produced <br />from the PV and battery system to keep the exported power below the limit set by the installer. <br />Aggregate power export limit can be supported in both configurations: grid-tied configuration (Solar <br />+ Battery or Solar only) and grid-forming configuration (Solar + Battery). For all supported SKUs with <br />aggregate power export limit, see Enphase Power Control in a grid-tied Enphase Energy System on <br />page 4. <br />5.4.1 Aggregate power export limit in the grid-tied configuration <br />In this configuration, the aggregate export power (Wexport) to the utility grid is monitored through the <br />Consumption CTs placed on the utility/grid side of the main panel. The power produced by the PV <br />and/or battery system is controlled appropriately to keep the Wexport less than or equal to the set <br />limit. <br />The following figure shows the aggregate power export limit in grid-tied and grid-forming <br />configurations, respectively. <br />Enphase Power Control features <br />38 © 2025 Enphase Energy Inc. All rights reserved. August 2025 <br />TEB-00269-2.0-EN